@article{PORMA_1978__37_1-2_115343,
     author = {Singmaster, D. and Souppouris, D.J.},
     title = {On the relationships among the axioms for a metric space and for general axiomatic systems},
     journal = {Portugaliae mathematica},
     pages = {145--155},
     publisher = {mathdoc},
     volume = {37},
     number = {1-2},
     year = {1978},
     mrnumber = {0620308},
     zbl = {0456.54020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1978__37_1-2_115343/}
}